Java

Java represents a number of computer software products and
specifications from Oracle Corporation (previously developed by Sun
Microsystems) that provide a system for
developing application software and deploying it in a cross-platform
environment.

Java is a network-aware language superficially resembling C
and C++, but much
smaller and more compact and cleanly designed. It's an unlimited-extent
language with garbage collection like Lisp, but with static type
checking.

The Java plaform consists of several programs including:

Java Virtual Machine (JVM), a set of computer software
programs and
data structures which use a virtual machine model for the execution of
other computer programs and scripts

Java Compiler

Java
Runtime Environment, executes .class or .jar files, emulating the JVM
instruction set by interpreting it, or using a just-in-time compiler
(JIT)

Class libraries provide:

a well-known set of functions to perform common tasks

an abstract interface to tasks that would normally depend
heavily on the hardware and operating system

APIs

The
vast majority of Java's source code has been released under the GPL.
However, there remains a few parts which are only distributed
as precompiled binaries, without source code.

Java

Price
Free to downloadSizeJRE 59MB (32-bit)
JDK 131MB (32-bit)
JRE 57MB (64-bit)
JDK 118MB (64-bit)
License
Most of the Java technologies have been released under GNU GPL, but
some remains proprietaryDeveloperOracle Corporation

Software written in the Java language run on any supported
hardware/operating-system platform. In other words, a program can be
written once, compiled once, and run on multiple operating systems

Java
syntax borrows heavily from C and C++ but it eliminates certain
low-level constructs such as pointers and has a very simple memory
model where every object is allocated on the heap and all variables of
object types are references